i 


Issued  May  2o,  1914. 

HAWAII  AGRICULTURAL  EXPERIMENT  STATION, 

E.  V.  WILCOX,  Special  Agent  in  Charge. 


Bulletin   No.  34. 


TOBACCO  INSECTS  IN  HAWAII 


D.  T.  FULLAWAY, 

ENTOMOLOGIST. 


JRY 


r.>o£R  THE  SUPERVISION  OF 

OFFICE  OF  EXPERIMENT  STATION'S, 
U.  8.   DEPARTMENT    OF    AGRICULTURE. 


WASHINGTON: 

GOVERNMENT  PRINTING  OFFICE. 

1914. 


Issued  May  25,  1914. 

HAWAII  AGRICULTURAL  EXPERIMENT  STATION, 

E.  V.  WILCOX,  Special  Agent  in  Charge. 


Bulletin   No.  34. 


TOBACCO  INSECTS  IN  HAWAII 


BY 

D.  T.  FULLAWAY, 

ENTOMOLOGIST. 


UNDER  THE  SUPERVISION  OF 

OFFICE  OF  EXPERIMENT  STATIONS, 

U.  8.   DEPARTMENT   OF   AGRICULTURE. 


WASHINGTON: 

GOVERNMENT  PRINTING  OFFICE. 

1914. 


HAWAII  AGRICULTURAL  EXPERIMENT  STATION,  HONOLULU. 

[Under  the  supervision  of  A.  C.  True,  Director  of  the  Office  of  Experiment  Stations,  United  States  Depart- 
ment of  Agriculture.] 

Walter  H.  Evans,  Chief  of  Division  of  Insular  Stations,  Office  of  Experiment  Stations. 

STATION  STAFF. 

E.  V.  Wilcox,  Special  Agent  in  Charge. 
J.  Edgar  Higgins,  Horticulturist. 

W.  P.  Kelley,  Chemist. 
T>.  T.  Fullaway,  Entomologist. 
C.  K.  McClelland,  Agronomist. 
Wm.  McGeorge,  Assistant  Chemist. 
Alice  R.  Thompson,  Assistant  Chemist. 
C.  J.  Hunn,  Assistant  Agriculturist. 
V.  S.  Holt,  Assistant  in  Horticulture. 
C.  A.  Sahr,  Assistant  in  Agronomy. 

F.  A.  Clowes,  Superintendent  Hawaii  Substations. 

J.    de   C.   Jerves,   Superintendent  Homestead  Substation. 
W.  A.  Anderson,  Superintendent  Rubber  Substation. 
J.  K.  Clark,  Superintendent  Waipio  Substation. 

G.  Copp,  Superintendent  Kula  Substation. 

(2) 


LETTER  OF  TRANSMITTAL. 


Honolulu,  Hawaii,  August  16,  1913. 
Sir  :  I  have  the  honor  to  submit  herewith  and  recommend  for  pub- 
lication as  Bulletin  No.  34  of  the  Hawaii  Experiment  Station  a  paper 
on  Tobacco  Insects  in  Hawaii,  by  D.  T.  Fullaway,  entomologist.  The 
extension  of  the  tobacco  industry  in  Hawaii  in  the  past  few  years 
has  made  desirable  a  further  study  of  the  insect  pests  of  tobacco^  and 
the  results  of  these  studies,  together  with  practical  recommendations 
for  the  control  of  tobacco  insects,  are  presented  in  this  bulletin. 
Respectfully, 

E.  V.  Wilcox, 
Special  Agent  in  Charge. 
Dr.  A.  C.  True, 

Director  Office  of  Experiment  Stations, 

TJ.  S.  Department  of  Agriculture,  Washington,  D.  C. 

Recommended  for  publication. 
A.  C.  True,  Director. 

Publication  authorized. 

D.  F.  Houston,  Secretary  of  Agriculture. 

(3) 


CONTENTS 


Page. 

Introduction : 5 

Insects  affecting  the  plant 5 

Cutworms 5 

Splitworm 8 

Pod-borer 10 

Hornworm 13 

Flea-beetle 16 

Minor  pests 17 

Insects  affecting  the  stored  product 18 

Cigarette  beetle 18 


ILLUSTRATIONS. 


Fig.  1.  Caradrina  reclusa,  a  cutworm  common  in  tobacco  fields 6 

2.  Frontina  arctappivora,  parasitic  on  cutworms 7 

3.  Ichneumon  koebelei,  parasitic  on  cutworms 8 

4.  Phthorimsea  operculella,  the  tobacco  splitworm 9 

5.  Limnerium  blackburni,  parasitic  on  splitworm 10 

6.  Heliothis  obsoleta,  the  tobacco  pod-borer 10 

7.  Phlegethontius  quinquemaculata,  the  tobacco  hornworm 14 

8.  Epitrix  parvula,  the  tobacco  flea-beetle 16 

9.  Lasioderma  serricorne,  the  cigarette  beetle 18 

(4) 


TOBACCO  INSECTS  IN  HAWAII.1 


INTRODUCTION. 

A  general  account  of  the  insects  known  to  feed  on  tobacco  was 
presented  as  a  bulletin  of  this  station  by  D.  L.  Van  Dine.2  This 
bulletin,  however,  was  prepared  while  the  experimental  work  on 
tobacco  was  still  in  progress  and  before  any  large  areas  had  been 
planted.  In  the  meantime  the  industry  has  become  established  and 
the  plantings  greatly  extended,  and  in  view  of  the  facilities  for  obtain- 
ing and  importance  of  having  actual  and  complete  information  in 
regard  to  the  pests  encountered  in  the  tobacco  fields,  the  entomo- 
logical work  reported  herein  was  begun  several  years  ago  and  con- 
tinued to  date.  The  present  paper,  then,  is  intended  to  supplement 
the  information  contained  in  the  previous  bulletin,  and  in  addition 
to  listing  the  insects  gives  an  account  of  the  distribution,  life  history, 
habits,  means  of  control,  and  natural  enemies  of  each  of  the  species 
enumerated,  together  with  other  data  gathered  through  study  and 
observation  during  the  course  of  the  work. 

The  principal  tobacco  pests  are  cutworms,  sphtworm,  pod-borer, 
hornworm,  flea-beetle,  and  cigarette  beetle.  Many  minor  pests  are 
also  encountered  without  being  especially  destructive.  These  may 
be  discussed  in  two  categories,  namely,  those  affecting  the  plant  and 
those  affecting  the  product. 

INSECTS  AFFECTING  THE  PLANT. 
CUTWORMS. 

Cutworm  is  a  general  term  used  to  designate  the  large  ground- 
inhabiting  caterpillars  of  the  noctuid  moths  which  usually  leave  their 
diurnal  retreats  at  night  to  feed  on  any  vegetation  at  hand.  ' '  Peelua ' ' 
is  the  native  word  by  which  these  worms  are  known.  The  Noctuidae 
are  represented  in  these  islands  by  35  or  more  native  and  introduced 
species.  Of  these,  however,  only  eight  are  commonly  found  in  culti- 
vated fields;  the  others  are  more  or  less  confined  to  the  mountains 
and  the  native  flora  and  are  not  generally  encountered  as  agricultural 

i  The  habits  and  life  histories  of  the  cutworms,  splitworm,  tobacco  pod-borer,  hornworm,  tobacco  flea- 
beetle,  and  cigarette  beetle,  and  a  number  of  pests  of  minor  importance  in  Hawaii  are  described,  and  prac* 
tical  recommendations  are  made  regarding  the  control  of  each  of  them. 

>  Hawaii  Sta.  Bui.  10. 

(5) 


6 

pests.  While  the  cutworms  as  a  group  are  generally  held  in  check  by 
very  efficient  parasites,  on  account  of  their  great  reproductive  pow- 
ers and  the-  wide  range  of  their  food  plants  they  are  seasonally  very 
destructive,  especially  in  newly  broken  or  poorly  cultivated  fields, 
when  a  dearth  of  food  compels  them  to  migrate  in  numbers.  The 
winter  months,  when  the  parasites  are  numerically  at  a  low  ebb  and 
the  reviving  vegetation  gives  the  cutworms  an  impetus  to  increase, 
are  usually  the  season  of  cutworm  activity  and  widespread  destruc- 
tion of  crops. 

Caradrina  reclusa  is  the  species  most  commonly  found  in  the 
tobacco  fields  in  Hawaii  (fig.  1).  This  is  a  recently  introduced 
species,  not  listed  in  the  Fauna  Hawaiiensis.  According  to  Swezey, 
it  was  first  noticed  in  numbers  in  1906,  although  Perkins  had  taken 


Fig.  1. —  Caradrina  reclusa,  a  cutworm  common  in  tobacco  fields:  a,  Larva;  b,  pupa;  c,  moth.    (Original.) 

specimens  a  few  years  previous  to  1906.  Its  habitat  is  given  as  Nil- 
giris,  Ceylon,  Borneo,  and  Fiji,  and  it  has  probably  come  to  Hawaii 
from  the  last-named  locality. 

A  full  account  of  its  life  history  is  given  by  Swezey,1  from  which  the 
following  data  are  taken : 

The  eggs  are  not  laid  in  a  mass  or  cluster,  but  are  scattered  around 
singly  or  in  small  numbers;  on  the  surface  of  grass  leaves  they  are 
sometimes  laid  in  rows;  they  are  also  at  times  placed  on  any  hard 
surface.  One  moth  in  captivity  laid  216  eggs.  It  died  after  four 
days. 

The  egg  is  hemispherical,  with  the  flattened  surface  next  the  leaf; 
it  is  ribbed  meridianally  with  about  30  ribs,  10  of  which  reach  the 
upper  pole;  there  are  also  slight  cross  ridges  between  the  ribs;  at  the 

i  Proc.  Haw.  Ent.  Soc.,  2  (1908),  No.  1,  p»  3. 


upper  pole  is  an  irregular  patch  of  reddish  color;  there  is  also  an  irreg- 
ular ring  of  the  same  color  at  about  one-third  the  distance  from 
pole  to  base  of  egg;  the  rest  of  the  egg  is  pale  green;  when  first  laid 
it  is  entirely  pale  green. 

The  full-grown  larva  is  26-32  mm.  long  and  almost  black.  The 
two  preceding  stages  are  more  mottled  and  variegated  with. black, 
brown,  olivaceous,  yellowish  and  whitish,  darker  colors,  however, 
predominating.  There  are  two  more  or  less  conspicuous  subdorsal 
rows  of  black  spots  on  segments  7-12  and  a  broad  paler  region  on 
dorsum  between  these,  in  the  middle  of  which  is  a  series  of  obscure 
lozenge-shaped  darker  spots.  The  head  is  mostly  black  except  the 
periphery  (i.  e.,  the  portion  covered  when  retracted),  which  is  pale 
brown.  There  are  two  conspicuous  whitish  subdorsal  spots  on  seg- 
ment 6,  and  the  posterior  subdorsal  parts  of  segment  12  and  upper 
parts  of  segment  13  are  yellowish.  The  spiracles  are  black  with  a 
yellowish  streak  below  them.  The 
tubercles  are  not  conspicuous  but 
about  the  same  color  as  their  sur- 
roundings, and  the  hairs  are  short. 
The  twelfth  segment  is  quite 
swollen.  The  duration  of  the  larval 
stage  is  30-40  days. 

The  pupa  is  formed  in  the  soil,  an 
inch  or  two  below  the  surface.  It 
is  13-15  mm.  long,  uniform  medium 
brown;  eyes  black;  whig,  leg,  and 
antenna!  cases  extending  to  apex  of     _ 

.  ,        .    ,         .       ,  .      A  TiG,2.—Frontina  archipphora,  parasitic  on  cut. 

fourth  abdominal  segment;  the  ar-  worms.  (From swezey.) 

ticulations  between  segments  4-7 

movable.  There  is  a  row  of  about  20  pits  on  dorsal  part  of  basal 
margin  of  segments  5,6,  and  7,  from  the  ends  of  which  a  band  of  punc- 
tures extends  around  the  ventral  side.  The  apex  of  the  abdomen 
is  blunt  and  rounded,  with  two  approximate  dark  spines,  the  tips  of 
which  converge  and  are  slightly  curved  ventrally.  The  pupal  period 
is  12-14  days. 

The  moth  is  described  as  follows: ' 

9  Pale  chestnut  brown.  Fore  wing  with  very  faint  traces  of  the  usual  markings; 
a  prominent  ochreous  postmedial  line  slightly  curved  from  the  costa  to  vein  2,  and 
not  waved.     Hind  wing  paler. 

<$  With  the  collar  and  abdomen  black;  the  second  joint  of  palpi  black.  Fore 
wing  with  the  basal  area  clothed  with  ocherous  hair ;  hind  wing  with  the  base  yel- 
lowish; some  specimens  have  a  black  speck  in  cell  of  fore  wing  and  series  of  specks 
on  the  postmedial  line  and  margin. 

On  the  few  productive  plantations  here  this  cutworm  is  by  long 
odds  the  most  destructive  pest  encountered.     Six  and  seven  replant- 

«  Hampson.    Fauna  Brit.  India;  Moths,  2  (1894),  p.  264. 


8 

ings  are  often  required  to  secure  a  stand,  in  spite  of  the  most  thorough 
distribution  of  poisoned  bait  and  handpicking.  Inability  to  control 
the  cutworms  in  these  plantations  is  due  largely  to  the  character  of 
the  land,  which  is  rocky  and  unworkable.  With  thorough  cultiva- 
tion, cutworms  become  almost  a  negligible  quantity  after  the  lapse 
of  several  years,  except  for  occasional  outbreaks  which  are,  for  most 
species,  of  rare  occurrence. 

Next  to  thorough  cultivation  the  best  artificial  control  of  cutworms 
is  secured  by  distributing  about  the  plants  a  poisoned  bait — white 
arsenic  or  Paris  green  in  moistened  and  sweetened  bran,  flour,  or 
middlings.  The  edges  of  fields  adjacent  to  uncultivated  land  are 
often  trenched,  so  as  to  present  a  steep  surface  on  the  exposed  side 
which  the  cutworm  can  not  climb.  Hand  picking  is  sometimes 
resorted  to,  but  is  altogether  too  slow  and  expensive, 

As  already  stated,  the  present  parasites  of  cutworms  are  fairly 

efficient  throughout  the 
year ;  these  are  the  tachinid 
flies,  Frontina  archippivora 
(fig.  2)  and  CJisetogsedia  mon- 
ticola,  the  ichneumon  fly, 
Ichneumon  Jeoebelei  (fig.  3), 
and  the  egg  parasite,  TricTio- 
gramma  pretiosa }  Birds 
also  devour  large  numbers. 
The  loss  from  cutworm  in- 
jury, especially  in  diversi- 
fied farming,  is  a  serious 
matter  and  should  have 
more  attention  than  it  at 
present  receives.  For  in- 
stance, with  Government  assistance  it  might  be  possible  to  get  by 
importation  many  additional  cutworm  parasites.  Insectivorous  birds 
also  should  be  protected  by  law  or  by  the  cooperation  of  owners  of 
land  used  for  agricultural  purposes,  and  more  insectivorous  species 
might  be  secured  by  importation. 

SPLIT  WORM. 

The  splitworm  of  tobacco  is  the  caterpillar  of  the  common  gelechiid 
moth,  Phihorimsea  operculella  (fig.  4),  a  widely  distributed  pest  of 
Irish  potatoes,  tomatoes,  eggplants,  and  other  solanaceous  plants, 
as  well  as  of  tobacco.  The  moth  was  described  in  1878  from  speci- 
mens from  Texas  and  its  destructiveness  to  solanaceous  plants  came 
to  notice  shortly  afterwards.  Within  a  decade  it  was  reported  as  an 
agricultural  pest  from  various  parts  of  the  United  States  and  the 


Fig.  3.— Ichneumon  koebelei,  parasitic  on  cutworms. 
Swezey.) 


(From 


i  This  parasite,  or  T.flavum,  which  is  probably  only  a  synonym  of  T.  pretiosa,  has  been  bred  from  the 
eggs  of  a  noctuid,  probably  Spodoptera  exigua. 


West  Indies,  from  Algeria  and  the  Canary  Islands  in  Africa,  and  from 
Australia  and  New  Zealand  in  Polynesia.  It  was  first  noticed  in 
Hawaii  in  1892  by  Perkins  and  Blackburn,  when  it  had  undoubtedly 
been  here  some  time. 

The  caterpillar,  as  indicated  in  the  designation  ''splitworm,"  mines 
the  leaves  of  its  host  plants,  making  a  broad,  flat  track  through  the 
mesophyll  between  the  upper  and  lower  epidermis,  which  often 
becomes  badly  split  and  shattered  when  dry.  It  sometimes  also 
tunnels  the  stem,  which  thereby  becomes  greatly  weakened. 

As  a  tobacco  pest  this  species  is  most  injurious  to  seed  bed  plants. 
When  the  seed  bed  is  invaded  the  plants  are  generally  set  back  and 
sturdy  seedlings  for  transplanting  difficult  to  obtain.  This  trouble 
may  be  partly  overcome  by  seeding  the  beds  very  thin  and  protecting 
them  from  the  moth  with  cotton  netting. 
The  damage  to  plants  in  the  field  is  slight 
on  well-conducted  plantations,  and  it  is 
usually  only  the  two  or  three  poor,  soiled, 
lower  leaves  that  are  much  split  by  the 
worm.  Where,  however,  a  planting  is 
neglected  the  infestation  becomes  general 
and  any  tobacco  in  proximity  to  the  neg- 
lected fields  will  be  badly  split. 

Life  history. — There  are  four  distinct 
stages  in  the  life  cycle  of  this  insect, 
namely,  the  egg,  larva  or  caterpillar,  pupa, 
and  adult. 

The  egg:  The  eggs  are  laid  singly  on  fig.  4—  puitonmxa  opercuieiia, the  to- 
the  leaves,  often  in  the  hollow  alongside  ^ES?i£?EJ^ 
the  veins.  They  are  oval  to  pear  shaped,  d,  pupa;  e,  /,  segments  of  larva, 
0.45  mm.  long  by  0.27  mm.  across,  pearly  eHn^agredd'  (Redrawn  from  Riley  & 
white,  and  faintly  reticulate.  About  20  to 
25  eggs  are  laid  by  a  single  moth.     The  eg^  stage  occupies  six  days. 

The  larva:  The  full-grown  larva  is  a  rather  slender  worm,  about 
10  mm.  long,  in  color  sordid  white  with  a  greenish  or  reddish  tinge; 
the  head,  cervical  shield,  legs,  and  antennae  brown  to  black.  The 
cervical  shield  is  broad  and  wide,  almost  reaching  the  posterior  margin 
of  the  segment;  the  lateral  hind  angles  rounded.  The  tubercles  are 
fuscous  to  black,  mostly  minute,  bearing  setae,  and  are  arranged  in 
longitudinal  rows  as  follows:  (1)  anterior,  (2)  posterior  and  a  trifle 
more  removed  than  1,  (3)  above  spiracle,  (4  +  5)  below,  (6)  posterior, 
below  fold,  (7)  ventral;  on  segments  2  and  3(1)  and  (2)  are  in  a  line 
at  about  middle  of  segment,  while  (3) ,  (4) ,  and  (5)  form  an  equilateral 
triangle,  (3)  and  (4)  rather  large;  on  first  segment  the  spiracle  is 
posterior,  and  in  front  of  it  there  is  a  large,  flat  tubercle  with  three 
long  hairs. 

34855°— 14 2 


b 


10 

The  larval  stage  occupies  about  26  days.  Before  pupating  the 
worm  usually  leaves  its  mine  or  tunnel  and  finding  a  hidden  or 
obscure  corner  builds  a  cocoon  of  silk  and  grass  or  grains  of  soil 
within  which  it  pupates. 

The  pupa:  The  pupa,  removed  from  its  case,  is  brown,  about  6 
mm.  long,  and  rather  slender.  The  wing  cases  distally  are  free  from 
the  abdomen;  the  leg  and  antennal  cases  are  scarcely  longer  than 
these,  and  reach  the  apex  of  the  sixth  segment.  The  cremaster  is 
lobed,  and  between  the  lobes  dorsally  is  a  short,  stout  spine  surrounded 
by  numerous  hairs  with  recurved  tips.  The  pupal  stage  covers  11 
days. 

The  moth:  The  moth  is  described  by  TValsingham  !  as  follows: 

Antennae  brownish  cinereous.  Palpi  cinereous,  with  two  umber-brown  patches 
on  the  median  joint  externally,  a  spot  of  the  same  on  the  base  of  the  terminal  joint 
and  a  broad  band  before  its  apex.  Head  brownish  cinereous;  face  pale  cinereous. 
Thorax  brownish  cinereous,  with  three  emoky  brown  longitudinal  lines  above. 
Fore  wings  dull  buff -brown,  shaded  and  spotted  with  dark  smoky  brown;  this  forms 
a  dorsal  shade  below  the  fold,  a  terminal  shade  reverting  around  the  apex,  and  a  spot 
at  the  end  of  the  cell  from  which  narrow  lines  radiate  outward  along  the  veins;  there 
are  also  two  spots  near  the  base  of  the  costa,  the  first  succeeded  by  another  below  and 
beyond  it,  the  second  followed  by  one  on  the  cell  and  one  on  the  fold  in  an  oblique 
line,  a  pair  of  smaller  spots  lying  beyond  this  line  on  the  cell,  also  in  oblique  succes- 
sion; cilia  pale  buff -brownish,  sprinkled  along  their  base  with  smoky  brown.  Exp. 
al.  1-5-16  mm.  Hind  wings  pale  gray;  cilia  pale  brownish  ochreous.  Abdomen  and 
legs  brownish  cinereous. 

Remedies. — As  the  insect  in  its  injurious  stage  is  generally  protected 
in  its  tunnel,  poisons  are  of  little  use  in  attempting  to  control  it 
artificially.  It  is  well  known,  however,  that  the  worm  often  deserts 
an  old  mine  to  form  a  new  one  and  the  hatching  caterpillars  must  in 
the  first  place  eat  through  the  epidermis;  to  this  extent,  therefore, 
they  are  vulnerable  to  lead  arsenate  dusted  or  sprayed  on  the  plants, 
and  this  measure  is  recommended  for  the  control  of  the  worm  in  seed 
beds.  If  the  arsenic  is  applied  as  a  spray  it  can  be  combined  with 
the  Bordeaux  mixture  used  in  case  of  fungus  troubles.  Under  field 
conditions,  however,  the  little  good  accomplished  and  the  great 
expense  involved  make  it  scarcely  worth  while.  As  already  men- 
tioned, the  beds  can  be  protected  by  screening.  As  a  precaution 
against  a  general  infestation,  no  solanaceous  plants  should  be  grown 
near  the  tobacco  fields  and  all  solanaceous  weeds  in  the  immediate 
vicinity  should  be  periodically  destroyed. 

Natural  enemies. — The  caterpillars  of  the  splitworm  are  very  much 
parasitized  by  a  small  black  and  white  braconid,  Cltdonus  hlaclcburni, 
which  likewise  attacks  a  number  of  other  small  leaf-rolling  cater- 
pillars. The  parasitized  caterpillars  spin  their  cocoons  when  about 
half  grown  without  pupating.     Shortly  afterwards  the  larva  of  the 

i  Fauna  Hawaiiensis,  vol.  1,  pt.  5,  p.  484,  1907. 


11 


Fig.  5. — Limnerium  blackburni,  parasitic  on  splitworm. 
(From  Swezey.) 


parasite  emerges  from  the  caterpillar  and  feeding  on  it  externally 
finishes  it  off  and  spins  its  own  delicate  white  cocoon  inside  that  of  its 
host.  The  parasite  emerges  a 
little  later  than  the  moth  would 
have  done.1 

It  is  also  much  parasitized  by 
a  native  ophionid,  Limnerium 
blackburni,  common  to  many 
of  the  smaller  pyralids,  and  with 
very  similar  habits  to  the  para- 
site referred  to  above. 

POD- BORER. 

The  tobacco  pod-borer,  more 
familiar  in  some  quarters  as  the 
cotton  bollworm  and  the  corn 
earworm,  is  the  larva,  or  cater- 
pillar, of  the  noctuid  moth  Heliotliis  obsoleta,  a  cosmopolitan  pest  of 
omnivorous  habit,  often  very  destructive  to  such  important  field  crops 

as  cotton,  corn,  tobacco,  toma- 
toes, etc.  (fig.  6) .  On  the  to- 
bacco plant  its  characteristic 
injury  is  the  boring  and  eat- 
ing of  the  seed  pods,  although 
it  also  eats  the  f oliage  to  some 
extent.  Curiously  enough,  in 
Hawaii  it  is  never  found  on 
either  corn  or  cotton  and  is  not 
generally  considered  a  serious 
pest  to  tobacco.  Its  multipli- 
cation is  probably  in  some  way 
checked  or  controlled,  most 
likely  by  natural  enemies, 
although  these  have  never 
been  disclosed. 

Life  history. — There  are  the 
usual  four  stages  in  its  de- 
velopment. 

Fig.  e.-Heliothis  obsoleta,  the  tobacco  pod-borer.  a,Adul  t  ^[le  f&&:  Ine  eggs  are  *aid 
moth;  b,  dark  full-grown  larva;  c,  light  colored  full-  singly,  in  a  Considerable  nUHl- 
grown  larva;  d,  pupa-natural  size.    (From  Howard.)       ^     ^     ^    generaUy    weE 

scattered.  They  are  rather  large  and  conspicuous;  sometimes  they 
are  found  near  the  bud  in  young  plants,  most  usually  however  on  the 
flower,  the  pod,  or  the  subtending  bracts,  rather  loosely  attached 


i  Hawaiian  Sugar  Planters'  Sta.,  Div.  Ent.  Bui.  5,  p.  41  (1907). 


12 

but  adhering  readily  to  the  sticky  surface  of  the  plant.  The  egg 
is  pearly  white,  spherical  (diameter  about  0.6  mm.),  radiately  ridged 
on  the  sides  from  a  smooth  circular  area  on  the  dorsal  summit  sur- 
rounding the  micropyle,  the  longitudinal  ridges  connected  by  short 
cross  ridges.     The  egg  stage  is  five  days. 

The  larva:  The  larva  is  extremely  variable  and  for  that  reason 
difficult  to  describe.  Freshly  hatched  specimens  are  about  0.75  mm. 
long,  sordid  white  with  black  head  and  fuscous  cervical  shield,  and 
covered  with  black  hairs.  Four  or  five  molts  occur  in  the  course  of 
its  growth,  the  color  often  changing  in  the  molt.  The  full  grown 
caterpillar  is  30-40  mm.  long,  stout  bodied,  the  integument  more  or 
less  shagreened  through  the  presence  of  extremely  closely  set,  short, 
stout  spines;  the  principal  varieties  greenish,  reddish,  and  grayish, 
and  longitudinally  striped — usually  a  broad  dorsal  and  two  broad 
lateral  dark  stripes  above  the  pale  stigmatal  line,  with  many  fine 
wavy  lines  intermixed.  The  head  and  cervical  shield  are  brown,  the 
latter  with  irregular  black  markings.  Spiracles  black  with  white 
center.  Tubercles  variable,  some  large  and  black,  others  small  and 
pale,  and  arranged  in  longitudinal  rows  as  follows:  On  segments  4-9 
(1)  is  anterior,  (2)  posterior  and  farther  removed  from  median  line, 
(3)  above  spiracle,  (4)  behind  and  (5)  under  and  beneath  the  stig- 
matal line;  in  some  cases  (4)  is  small  and  (5)  is  in  all  cases.  On  the 
segments  with  prolegs  (6)  is  above  the  leg;  on  the  segments  without 
them  (6)  and  (7)  are  ventral  and  posterior.  On  segments  2  and  3 
(1)  and  (2)  are  in  line  and  (1)  is  smal];  (3)  is  close  to  (2)  and  also  in 
line;  (4)  and  (5)  are  small,  the  latter  behind  the  former  on  the  stig- 
matal fine,  (6)  above  the  leg.  On  segment  1  (1)  is  anterior,  (2)  pos- 
terior and  farther  removed,  (3)  is  above  spiracle,  (4  +  5)  in  front, 
(6)  above  the  leg.  On  segment  10  (4)  is  behind  (5),  which  is  below 
the  spiracle;  on  segment  11  (4)  is  absent.  The  length  of  the  larval 
stage  is  32  days.  When  full  grown  the  larva  leaves  the  plant  to 
enter  the  soil,  fashioning  a  rough  cell  several  inches  below  the  surface 
in  which  it  pupates. 

The  pupa:  The  pupa  is  of  the  usual  stout  noctuid  type;  length 
about  20  mm. ;  smooth  and  brown.  The  wing  cases  end  broadly,  the 
leg  and  antennal  cases  narrowly,  at  the  apex  of  segment  4.  The 
spiracles  on  segments  2-7  are  contracted  oval,  raised  above  the  in- 
tegument into  a  short  neck,  and  are  black;  that  on  segment  8  is  a  mere 
narrow  slit.  The  anterior  margin  of  segments  4-7  dorsally  and  5-7 
ventrally  are  punctate,  the  punctation  rather  fine  on  segment  4, 
otherwise  coarse.  The  cremaster  is  rather  pointed,  with  two  fairly 
long  projecting  spines.     The  length  of  the  pupal  stage  is  12-16  days. 

The  moth:  The  adult  moth  is  described  as  follows:1 

i  Hampson.    Fauna  Brit.  India;  Moths,  2  (1894),  p.  174. 


13 

Ochreous  with  a  pale  brown,  olive,  or  red-brown  tinge.  Fore  wing  with  indistinct 
double  waved  antemedial  lines;  a  dark  speck  representing  the  orbicular;  an  indistinct 
curved  medial  line;  the  reniform  indistinct ;  postmedial  and  sub  marginal  waved  lines, 
the  space  between  them  somewhat  darker  and  with  a  series  of  pale  or  dark  specks  on 
the  nervules;  a  marginal  series  of  dark  specks.  Hind  wing  white;  the  veins  fuscous; 
a  broad  blackish  outer  border  usually  with  a  pale  submarginal  central  patch.  Under- 
side of  fore  wing  with  the  orbicular  and  reniform  stigmata  conspicuously  black;  a 
broad  blackish  band  beyond  the  postmedial  line;  the  apices  of  both  wings  and  outer 
area  of  fore  wing  pinkish. 

Remedies. — As  already  stated,  the  pod-borer  is  not  a  serious  pest 
of  tobacco.  It  is  the  general  practice  of  planters  to  top  the  plants 
as  soon  as  the  flowers  appear,  and  where  this  is  done  consistently 
there  is  little  evidence  of  the  pod-borer.  To  obtain  seed,  the  flower 
stalks  are  usually  inclosed  in  a  bag.  Neglected  fields,  however, 
always  show  signs  of  the  borer  if  the  eggs  or  worms  are  not  actually 
present  in  numbers.  Under  the  circumstances  it  is  unnecessary  to 
recommend  any  remedial  measures  beyond  the  avoidance  of  neglecting 
a  regular  routine  in  field  work.  If  for  any  reason  a  field  of  standing 
tobacco  is  abandoned,  the  plants  should  be  plowed  up  and  destroyed 
to  avoid  a  general  infestation. 

Natural  enemies. — The  eggs  of  the  pod-borer  moth  are  probably 
parasitized,  here  as  elsewhere,  by  Tricliogramma  pretiosa,  although 
the  parasite  has  never  to  my  knowledge  actually  been  bred  here  from 
Heliothis  eggs.  It  is  also  possible  that  the  common  tachinid  parasites 
attack  Heliothis,  but  there  is  no  positive  evidence  at  hand.1 

HORN  WORM. 

Horn  worms  are  the  familiar,  large,  repulsive-looking  caterpillars  of 
the  hawk  moths,  with  large  head  and  prominent  horn  or  spine  at  the 
hind  end  of  the  body.  The  moths  are  also  large  and  heavy-bodied 
and  resemble  humming  birds  as  they  hover  around  open  blossoms  in 
the  late  afternoon.  There  are  several  native  species  which  are  only 
rarely  seen  in  the  mountains,  but  the  strong  flying  moths  often  get 
down  to  the  coast.  The  commoner  introduced  species  are  found, 
Sphinx  convolvuli  on  sweet  potatoes  and  DeUepJiila  lineata  on  purslane. 
The  tobacco  hornworm,  Pldegeihontius  quinquemaculata  (fig.  7),  is 
extremely  uncommon  and  has  never  been  seen  by  the  writer  on 
tobacco.  It  is  sometimes  found  around  Honolulu  on  the  wild  tobacco 
(Xicotiana  glauca),  and  on  these  occasions  the  broods  are  usually  large, 
and  the  plants  soon  stripped.  Its  rare  occurrence  would  indicate 
the  presence  of  very  efficient  parasites. 

The  tobacco  hornworm  is  a  North  American  insect  and  is  known 
throughout  the  tobacco  districts  of  the  United  States  as  the  northern 
tobacco  worm  in  contradistinction  to  the  southern  tobacco  worm, 
P.  sexta.     It  must  have  been  introduced  here  at  an  early  date;  it 

i  Since  the  above  was  written,  Frontina  archippivora  has  been  bred  from  the  pupa. 


14 

was  first  recorded,  however,  by  Blackburn  in  1881  and  described  by 
Butler  on  Blackburn's  specimens  as  a  new  species,  P.  blaclcburni. 
P.  Uackburni  later  proved  to  be  a  synonym,  as  already  indicated. 
The  larva:  The  larva  is  described  by  Blackburn  as  follows:1 
Green  or  ashy  gray,  more  or  less  sprinkled  with  white;  spiracular  line  white, 
emitting  upwards  and  backwards  (i.  e.,  so  that  they  slant  upwards  in  a  backward 
direction)  seven  white  stripes,  the  first  of  which  is  on  the  fourth  segment  (not  counting 
the  head  as  a  segment),  the  last  on  the  tenth;  on  the  eleventh  segment  is  a  small  white 
stripe  bent  backwards  over  the  spiracle,  being  much  smaller  than  the  white  lines 
on  the  other  segments;  head  with  two  well-defined  black  longitudinal  lines,  and 
clouded  with  black  laterally;  spiracles  black,  surrounded  with  a  bright  blue  ring; 


Fig. 


-Phlegethontius  quinquemaculata,  the  tobacco  hornworm.    c,  Adult  moth;  6,  full-grown  worm 
or  larva;  c,  pupa— natural  size.    (From  Howard.) 


horn  long,  shining  black,  bent  backwards;  claspers  of  the  ground  color.  In  the 
ashy  gray  larvae  the  whole  dorsal  surface  is  sprinkled  with  white;  the  segment  behind 
the  head  is  shining  black,  bordered  with  white;  the  last  claspers  and  space  around 
the  anus  are  shining  black  (at  least  partially);  and  the  legs  are  blackish  at  base, 
becoming  red  toward  apex.  In  the  green  larvse  only  a  few  segments  near  the  head 
are  sprinkled  with  white,  and  the  segment  next  behind  the  head,  the  last  claspers, 
and  the  space  round  the  anus  are  olivaceous  rather  than  black;  the  legs,  too,  are  more 
conspicuously  red. 

The  pupa:  The  pupa  is  of  the  usual  large  heavy-bodied  sphingid 
type  with  projecting  tongue  case  forming  the  so-called  "jug  handle. " 


i  Ann.  and  Mag.  Nat.  Hist.,  5.  ser.,  7  (1881),  p.  319. 


15 

It  is  described  as  rather  slender  and  more  or  less  smooth,  the  punc- 
turing at  base  of  abdominal  segments  and  at  apex  fine  and  shallow. 
The  wing  cases  are  angulate,  the  tongue  case  rather  long  and  thin, 
the  tip  touching  the  body  at  one-third  the  length  from  the  head. 
The  larvae  pupate  3  or  4  inches  deep  in  the  soil  within  a  roughly 
constructed  cell. 

The  moth :  The  moth  is  described  as  follows : 1 

General  color  ask  gray;  fore  wings  ash.  gray  at  base,  without  white  spots.  Xo  white 
dot  at  middle  of  wing,  this  mark  represented  by  a  gray  dot  encircled  with  black, 
which  does  not  contrast  with  the  color  of  adjacent  parts.  Fringe  of  outer  margin 
without  white.  An  evident  whitish  line  begins  in  an  enlargement  at  the  angle,  and 
extends  forward,  parallel  with  the  edge,  toward  the  apex  of  the  wing,  but  terminates 
abruptly  before  reaching  it.  Outer  angle  of  fore  wing  decided.  Basal  two-thirds 
of  hind  wing  largely  light  ash  gray,  the  middle  of  the  wing  crossed  by  two  sharply 
dentate  black  lines,  which  represent  the  more  or  less  fused  pair  on  the  wing  of  P. 
Carolina.  Outer  third  of  hind  wing  largely  ash  gray,  this  area  limited  within  by  a 
wide  curved  band  of  black.  Head  and  thorax  above  ash  gray.  Abdomen  on  middle 
above  ash  gray,  with  an  evident  narrow  median  black  line.  Orange  spots  on  side 
five  in  number,  less  elongated  transversely  and  more  rounded  than  in  the  related 
species.     Legs  gray,  cross-banded  with  whitish  above. 

The  following  description  of  the  Hawaiian  form  is  copied  from 
Butler:2 

P.  quinquemaculato  simillima;  major,  alis  latioribus,  magis  grisescentibus;  signis 
alarum  anticarum  subcostalibus  albescentibus;  serie  macularum  albarum  antice 
confiuentium  arcuata  discali,  cum  fascia  ordinaria  nigrocincta  cohaerente;  fasciola 
posticarum  prima  obsoleta;  fascia  sub-marginali  nigra  apud  apicem  multo  latiore; 
alar.  exp.  unc.  5. 

There  are  no  breeding  records  at  hand . 

In  the  United  States  the  life  cycle  runs  through  about  45  days;  in 
Hawaii  the  time  would  presumably  be  somewhat  shorter. 

Remedies. — As  already  stated,  tobacco  growers  have  not  found  the 
hornworm  a  serious  pest  on  account  of  its  rarity.  When  it  does 
appear  it  may  flourish  for  a  time  and  do  considerable  damage;  in 
such  a  case  it  is  best  to  check  it  at  once  by  spraying  infested  plants 
with  lead  arsenate  (3  pounds  to  100  gallons  of  water),  to  which  the 
young  worms  are  very  susceptible.  If  the  worms  have  reached  large 
size  before  the  infestation  has  been  noticed,  hand-picking  should  be 
resorted  to,  as  it  is  difficult  to  kill  the  large  worms  with  a  stomach 
poison. 

Natural  enemies. — The  natural  enemies  are  not  known,  but  it  is 
probably  an  egg  parasite  and  not  unlikely  a  trichogrammid.  The 
eggs  of  the  congener  S.  convolvuli  are  parasitized  by  the  trichogrammid 
Pentarthron  semifuscatum. 

iGarman.    Kentucky  Sta.  Bui.  66,  p.  25.  2  Ent.  Mo.  Mag.,  17  (1880),  p.  6. 


16 


FLEA-BEETLE. 


The  tobacco  flea-beetle,  Epitrix  parvula  (fig.  8),  is  one  of  thephy- 
tophagid  beetles,  a  family  including  many  extremely  injurious  forms, 
such  as  the  10-lined  potato  beetle,  the  asparagus  beetle,  cucumber 
beetle,  and  a  host  of  other  flea-beetles  with  very  similar  habits  but 
widely  different  food  plants. 

According  to  Sharp,1  who  vouchsafes  for  its  specific  identity,  it  is  a 
late  introduction,  not  being  taken  by  Blackburn  in  his  collecting  here 
m  the  late  seventies  and  early  eighties.  It  is  of  American  origin  and 
is  generally  distributed  in  the  Southern  States  of  the  Union,  in  Mex- 
ico, Central  America,  and  the  West  Indies.  Like  some  other  tobacco 
pests,  it  feeds  on  practically  all  the  commoner  solanaceous  plants,  and 
is  equally  injurious  to  potatoes,  tomatoes,  eggplant,  and  poha.     Both 

the  larva  and  the  adult  beetle  do 
damage,  but  the  characteristic  in- 
jury is  the  work  of  the  adults  on 
the  leaves.  The  beetles  are  small 
and  their  mouth  parts  can  grasp 
only  small  fragments,  but  they  are 
assiduous  feeders,  so  that  the  re- 
sult of  their  feeding  is  often  a 
shattered  foliage,  ragged  with  spots 
and  holes  and  broken  margins. 
The  larvae  work  beneath  the  sur- 
face on  the  roots  and  crown,  an 
injury  apparently  of  little  conse- 
quence, but  noticeable  in  neglected 
plants.  No  enemies  have  been  dis- 
closed, but,  apparently,  some  factor 
interferes  to  prevent  its  undue 
multiplication,  else  this  pest  would  do  widespread  injury.  In  some 
places  there  appears  to  be  a  seasonal  occurrence,  the  beetle  becoming 
numerous  and  injurious  only  in  the  dry  season;  but  in  neglected 
plantations,  and  especially  in  the  neighborhood  of  other  solanaceous 
plants,  it  is  commonly  prevalent.  The  adult  beetle  is  rather  long 
lived,  but  it  should  not  on  this  account  necessarily  be  more  injurious, 
as  it  is  able  to  do  without  food  for  long  periods. 

The  difficult  life  history  has  been  fully  studied  in  America  by  Chit- 
tenden, and  the  writer  has  not  attempted  to  duplicate  this  work. 

Egg:  The  egg,  according  to  Chittenden,2  is  narrow,  elliptical-ovate, 
two  and  one-half  times  as  long  as  wide,  color  gray  with  scarcely  a 


Fig.  8. — Epitrix  parvula,  the  tobacco  flea-beetle. 
a,  Adult  beetle  enlarged  about  fifteen  times;  6, 
young  larva;  /,  pupa;  c,  d,  e,  portions  of  the 
larva  greatly  enlarged.    (From  Chittenden.) 


i  Fauna  Hawaiiensis,  vol.  2,  pt.  3,  p.  95, 1900. 

2  U.  S.  Dept.  Agr.,  Div.  Ent.  Bui.  19,  n.  ser.,  p.  86  (1899). 


17 

tinge  of  yellow,  the  surface  divided  into  very  minute  irregular  areas 
only  visible  under  a  high  magnification.  Length  0.4  mm.,  width 
0.18  mm. 

Larva:  The  larva,  according  to  the  same  authority,1  is  3.5  mm. 
long,  delicate  and  filiform  or  threadlike,  milky  white  in  color  except 
the  head,  which  is  honey  yellow,  and  with  darker  brown  mouth  parts 
and  sutures.  The  body  is  subcylindrical,  moderately  wrinkled  and 
segmented,  and  sparsely  covered  with  short  hairs.  The  head  is  only 
moderately  chitinized,  and  the  first,  thoracic,  and  last,  or  anal,  seg- 
ment are  apparently  not  at  all  or  only  slightly  chitinized.  The  anal 
segment  is  furnished  with  a  small  proleg,  but  there  are  no  visible  den- 
ticles at  its  apex. 

Pupa:  The  pupa  is  white  like  the  larva  and  resembles  the  pupa  of 
Diabrotica,  especially  in  the  anal  hooklike  appendages.  The  insect 
pupates  in  a  cell. 

Adult:  The  adult  is  very  minute,  measuring  scarcely  1.5  mm.  in 
length,  is  oblong  ovate  in  form,  and  light  brown  in  color.  The 
elytra  are  usually  marked  with  a  dark  transverse  median  band  of 
greater  or  less  extent. 

A  life  cycle  is  said  to  run  through  28  days,  as  follows:  Egg,  6  days; 
larva,  16  days;  pupa,  6  days.  In  Hawaii  it  would  presumably  be 
somewhat  shorter. 

Remedies. — On  the  commercial  plantations  of  Hawaii  the  flea- 
beetle  does  not  seem  to  be  much  of  a  pest  except  late  in  the  growing 
season,  but  in  neglected  tobacco  it  becomes  very  numerous.  For  this 
reason  it  is  necessary  in  growing  tobacco  commercially  to  keep  well 
up  in  the  field  work  and  allow  no  plants  to  remain  around  after  the 
tobacco  has  been  picked.  Other  solanaceous  crops  should  not  be 
grown  near  the  tobacco,  and  all  solanaceous  weeds  in  the  neighbor- 
hood should  be  periodically  destroyed.  When,  however,  the  flea- 
beetle  is  present  in  sufficient  numbers  to  damage  the  crop,  the  affected 
plants  may  be  sprayed  with  arsenate  of  lead,  1  pound  to  20  gallons  of 
water,  paste  form  (only  one-half  of  this  amount  of  powdered  arsenate 
of  lead),  which  will  kill  any  beetles  feeding  on  the  sprayed  foliage. 

MINOR    PESTS. 

There  are  a  few  minor  pests  of  tobacco,  such,  for  instance,  as  the 
caterpillars  of  Plusia  chalcites  and  of  Amorbia  emigrateUa,  which  are 
rather  general  feeders  and  are  found  on  various  cultivated  and  wild 
plants  without  being  particularly  injurious  to  all  of  them;  and  the 
mealy  bugs  Pseudococcus  citri  and  Pseudocoecus  virgatus,  which  are 
also  found  on  many  different  plants  but  are  noticeably  injurious  only 
under    exceptional    circumstances.     In    the    Kona    tobacco    fields 

i  U.  S.  Dept.  Agr.,  Div.  Ent.  Bui.  10,  n.  ser.,  p.  79  (1898). 


18 

Siphanta  acuta  and  Pulvinaria  psidii  are  also  found  on  tobacco, 
although  they  are  commoner  on  the  coffee  plant,  and  snails  do  some 
damage  to  seedling  and  young  plants.  The  grasshoppers,  Elimsea 
appendiculata  and  Xiphidium  varipenne,  are  frequently  seen  on 
tobacco  and  may  feed  on  it  to  some  extent,  but  the  injury  they  do  is 
altogether  negligible.  A  rather  common  introduced  bug  (Nysius 
delectus)  is  also  found  on  the  seed  pods  of  tobacco  wherever  grown, 
but  it  has  not  been  ascertained  whether  or  not  it  breeds  on  tobacco 
or  is  in  any  way  injurious  to  the  plant.  There  is  also  associated  with 
tobacco  a  bark  beetle  (Xyleborus  sp.)  the  larva  of  which  mines  the 
old  stems,  but  it  is  not  especially  injurious. 

INSECTS  AFFECTING  THE   STORED  PRODUCT. 
CIGARETTE    BEETLE. 


The  cigarette  beetle,  Lasioderma  serricorne  (Ptinidse)  (fig.  9),  is  one 
of  those  numerous  species  which  feed  altogether  on  dry,  dead  vegetable 


Fig.  9.— Lasioderma  serricorne,  the  cigarette  beetle,  a,  Larva;  6,  pupa;  c  and  d, 
adult;  e,  antenna— greatly  enlarged— natural  size  shown  by  hair  line.  (From 
Chittenden.) 

or  animal  substance,  and  thus  become  pests  where  animal  and  vege- 
table products  must  be  stored  or  kept  for  future  use.  Commercial 
operations  and  the  transference  of  stored  products  from  one  region 
to  another  have  gradually  brought  about  a  world-wide  dissemination 
of  many  of  these  species,  which  in  the  Tropics  are  especially  injurious 
and  difficult  to  control.  The  attachment  of  the  cigarette  beetle  to 
tobacco,  a  commodity  in  universal  use,  has  given  this  species  peculiar 
opportunity  to  attain  a  wide  distribution,  and  it  is  now  known  as  a 
practically  cosmopolitan  pest.  It  breeds,  however,  in  various  stored 
products  in  addition  to  tobacco — animal  as  well  as  vegetable — and 
often  becomes  a  household  pest,  attacking  the  coverings  of  walls  and 
furniture. 

It  was  first  recorded  from  Hawaii  by  Blackburn  in  1885  1  and  is 
undoubtedly  of  early  introduction.  Previous  to  commercial  tobacco 
growing  it  occasionally  came  to  notice  as  a  pest  in  houses  and  stores, 
especially  in  tobacconists'  shops  in  cigar  cases,  and  was  easily  con- 

i  Sci.  Trans.  Roy.  Dublin  Soc,  2.  ser.,  3  (1885),  p.  243. 


19 

trolled  by  fumigation,  the  damage  done  usually  being  slight.  How- 
ever, with  the  commercial  production  of  tobacco  and  the  necessity  of 
storing  large  quantities  of  tobacco  in  warehouses  over  long  periods, 
the  cigarette  beetle  has  become  a  serious  pest  in  the  tobacco  districts 
and  its  control  is  not  at  all  easy — indeed,  it  is  often  practically  impos- 
sible— and  serious  damage  to  the  stored  leaf,  before  it  can  be  sold  or 
manufactured,  is  unavoidable. 

There  is  very  little  information  of  a  historical,  descriptive,  or  bio- 
graphic nature  in  regard  to  the  cigarette  beetle.  On  account  of  its 
peculiar  habits  and  common  occurrence,  however,  the  beetle  is 
unusually  well  known  even  to  the  business  man.  It  can  be  recog- 
nized from  the  following  brief  description:  The  eggs  are  said  to  be 
white  and  very  minute.  The  larva  is  a  short,  stout,  hairy,  sordid 
white  grub,  between  3  and  4  mm.  long,  with  well-defined  chitinized 
head  and  three  pairs  of  short  legs.  The  integument  of  the  body  is 
much  wrinkled  and  the  body  itself  is  usually  somewhat  bent.  The 
adult  beetle  is  about  2.5  mm.  long,  reddish  brown,  and  covered  with 
pale  hairs.  The  antennae  are  regularly  serrate  and  fairly  long.  The 
male  is  slightly  smaller  than  the  female. 

Mackie  x  in  the  Philippines  states  that  eggs  hatch  1 1  days  after 
deposition  and  that  the  pupal  stage  covers  15  days.  The  length  of 
the  larval  stage  is  not  given. 

Remedies. — The  usual  method  of  destroying  the  cigarette  beetle  is 
to  expose  it  to  the  action  of  poisonous  gases,  either  the  fumes  of 
carbon  bisulphid  or  of  hydrocyanic-acid  gas.  This  method  gives 
admirable  success  where  the  infestation  is  only  incidental  and  local 
and  the  infested  material  can  be  placed  in  a  tight  compartment  so 
that  the  gases  can  be  confined  and  their  full  strength  utilized.  But 
when  the  infestation  becomes  general,  as  in  warehouses  in  which 
stored  products  are  being  continually  handled,  it  is  exceedingly  diffi- 
cult to  control  the  beetle  with  gases  or  by  any  other  means,  and  the 
only  relief  that  can  be  obtained  is  in  a  systematic  fumigation  of  the 
whole  warehouse  from  time  to  time,  or  different  parts  of  it  which  can 
be  rendered  tight  against  the  diffusion  of  the  gas.  Sometimes,  also, 
it  is  a  distinct  advantage  to  spray  the  floors  and  walls  with  benzine 
or  kerosene.  In  the  tobacco  industry,  baled  tobacco  offers  the  great- 
est resistance  to  palliative  measures,  and  no  satisfactory  method  of 
treatment  has  yet  been  devised  for  it.  Manufactured  goods  are  often 
kept  in  cold  storage  to  prevent  beetle  injury,  and  as  the  insect  is 
unable  to  develop  in  the  presence  of  such  low  temperatures  (32  to 
34°  F.),  the  goods  are  safe  while  in  storage  and  if  not  removed  too 
soon  the  danger  of  injury  after  withdrawal  is  greatly  reduced.  It 
has,  however,  been  shown  that  even  low  temperatures  continued  for 

»  Philippine  Agr.  Rev.,  4  (1911),  No.  11,  p.  607. 


20 

long  periods  are  not  sufficient  to  destroy  the  vitality  of  the  eggs  of 
the  cigarette  beetle  and  the  freezing  method  is  therefore  not  abso- 
lutely preventive. 

In  fumigating  with  carbon  bisulphid  use  it  at  the  rate  of  1  pound 
to  600  to  800  cubic  feet  of  air  space,  pouring  the  liquid  out  into  shallow 
pans  near  the  ceiling  (the  gas  is  heavier  than  air);  first  making  the 
building  or  compartment  as  tight  as  possible  against  leakage  of  the 
gas.  Small  lots  of  infested  tobacco  can  be  fumigated  in  air-tight 
boxes,  using  1  ounce  of  carbon  bisulphid  to  50  to  60  cubic  feet  of  air 
space.  Caution  is  advised  in  the  use  of  this  chemical  on  account  of 
its  poisonous  and  inflammable  nature. 

Hydrocyanic-acid  gas  is  perhaps  not  so  effective  against  stored- 
product  insects  as  carbon  bisulphid,  but  has  advantages  irucost  and 
ease  of  use.  It  is  generated  by  placing  cyanid  of  potassium  in» sul- 
phuric acid  and  water.  It  is  lighter  than  air,  and  therefore,  contrary 
to  the  rule  with  carbon  bisulphid,  should  be  generated  beneath. 
Use  in  proportions  of  1  ounce  of  98  per  cent  pure  cyanid,  1  fluid  ounce 
of  commercial  sulphuric  acid,  and  2  fluid  ounces  of  water  to  100  cubic 
feet.  Care  must  be  exercised  in  using  this  treatment  on  account  of 
the  very  poisonous  nature  of  the  cyanid  gas. 

Natural  enemies. — A  Pteromalus  was  bred  from  this  species. 


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